CUBE Technology has created an extremely compact and efficient enclosed combustor dubbed a Micro-Furnace. These Micro-Furnaces have demonstrated an unprecedented operating range and have operated on fuels from hydrogen to alcohol to JP-8. This Micro-Furnace combustor will be the core of the flameless personal water heater. This combustor is fast-starting and delivers its heat via radiation and convection. The Micro-Furnace will be used to heat small portions of water in a cup. The system will be designed to prevent JP-8 contamination of the water yet provide intimate contact between heated surfaces and the water to be heated. In addition, this system will incorporate a small power converter between the Micro-Furnace and the water to make it self-powered after a short start-up time allowing the personal water heater to be used repeatedly without external power and requiring only fuel to continue operating reliably.